‘Tonkotsu’ broth: A cure for sore vocal cords or an urban legend?

Yuichi Jose poses over a bowl of tonkotsu ramen. “I eat this dish after overusing my throat or on the morning of the day when I will be overusing it,” he says. (Provided by Across Entertainmento inc.)

FUKUOKA--A voice actor and two singers swear by “tonkotsu” soup, or pork bone broth, as a soothing remedy for their sore and overused throats.

But before you down bowls and bowls of tonkotsu ramen in hopes of becoming Japan’s next star vocalist, researchers and chefs say there is no definitive proof that Fukuoka’s specialty noodle dish produces such therapeutic effects.

At least not yet.

Yuichi Jose, a voice actor who appears on the “Ensemble Stars!” game app and serves as a narrator for TV programs, stands by his claim.

“(Tonkotsu soup) works immediately, so it’s a lot of help,” said the 32-year-old, whose last name is pronounced as in Spanish.

In 2011, Jose played the hero of a squadron in a play performed in Tokyo. His character had to wail and shout, and Jose complained about a sore throat during rehearsals that lasted for about a month.

He found relief by drinking kudzu starch gruel, but the effects were only temporary.

However, when he ate tonkotsu ramen, his favorite dish from his student years, he felt as if “a coating had been applied on the mucous membrane of the throat,” so he began consuming the dish more frequently.

Singer May J. also said on a TV program in 2014, “I found my voice quite mellow when I returned to a recording session after eating tonkotsu ramen.”

And vocalist Leo Ieiri, a native of Fukuoka Prefecture, said on a radio program, “Eating (tonkotsu) soup provides moisture to a gravelly throat.”

But officials of the singers’ production companies sounded reserved when asked about the remarks about eating tonkotsu ramen.

“She was doing that for some time, although she does not do so any longer,” said an official in charge of May J.

An official in Ieiri’s production company said, “She probably stopped the practice (of eating tonkotsu ramen) for health reasons, such as the high salt content.”

Tonkotsu soup is prepared by simmering pork bones for eight to 10 hours, said Masao Otsuka, proprietor of the Mappe ramen restaurant in Iizuka, Fukuoka Prefecture.

“The bones are simmered until they are soft and crushable, so their ingredients do come out,” Otsuka, 51, said. But he said he has never heard that tonkotsu broth is good for the throat.

“Perhaps the collagen that comes out of bone marrow has a moisturizing effect,” said Yoshinori Yamamichi, the 49-year-old head of research and development at Fukuoka-based Marutai Co., which produces the popular Bo Ramen (stick-shaped instant ramen). “The broth also abounds in fat. But ‘perhaps’ is all that I’m saying.”

Koji Abo, a specially appointed professor at Kurume Shin-ai College in Kurume, Fukuoka Prefecture, said he has studied the nutritional value of tonkotsu ramen. But on whether the dish soothes sore throats, he also used the word “perhaps.”

“The high content of collagen and lipids is a notable feature of the dish,” Abo, 67, said. “Perhaps the lipids and the collagen, the latter being in gel form halfway between solid and liquid phases, each work to protect the throat.”

Hideki Shiratsuchi, director of the Shiratsuchi ear, nose and throat clinic in Fukuoka’s Minami Ward, said that under normal circumstances, moisture in the entire throat, including the vocal cords, is essential for ensuring a voice that is loud and firm.

“Conceivably, the fat content may have a moisturizing effect that soothes swelling and inflammation in the vocal cord region,” said Shiratsuchi, 48, who is also a clinical professor with the Kyushu University School of Medicine.

He said that one currently practiced therapy involves injecting collagen into contracted vocal cords of patients who are losing their voices.

When asked about the soothing effects of tonkotsu broth, however, Shiratsuchi said, “Nobody has ever studied such a subject.”